Abstract: A power wrench operated with a pressure medium comprises a wrench head casing (10) which is engaged by a piston-cylinder unit (28,29). The other end of the piston-cylinder unit (28,29) is pressing against a support element (27) guided on a guideway (22) of the wrench head casing (10). The outer end (28) of the support element is applied to a stationary abutment. Upon rotating the wrench head (10) the ring (11) retaining the bolt or screw head is entrained by a ratchet (15) only in one sense of rotation, while the wrench head casing (10) is returned idly without entrainment of ring (11) in the other sense of rotation.

Abstract: The rotary tool contains a gear portion (16) whose input shaft (26) is driven by a hydraulic motor. The input shaft (26) is coupled with the output shaft (31) via an overload clutch (35,36,42) to ensure that with a low load, the transmission ratio is 1:1. With a higher load, the overload clutch automatically disengages so that the drive will be effected from the input shaft (26) via a double-stage sun-and-planet gear to the output shaft (31) which then is turning at a lower speed. Between the first stage (I GS) and the second stage (II GS) of the reduction gear, there is an overrunning clutch (52) which only couples with each other the two gear stages if the output shaft (31) turns more slowly than the input shaft (26).

Abstract: The screw assembly comprises a drive unit whose output shaft (14) can be connected with a button die to be applied to a screw head.To prevent the casing (10) of the drive unit from rotating, it is fitted with a retainer (24) which is placed against a solid abutment.The retainer (24) has a ring (23) enclosing the output shaft and being connected via a torsionally elastic element (16) with the casing (10).Torsional deformation of the torsionally elastic element (16) is used as a measure for the torque acting on the screw head. (FIG. 1).

Abstract: In a friction clutch having a housing and levers mounted on the housing for actuating at least one pressure plate, the levers engaging the pressure plate through a connecting linkage, the levers being formed of at least two sheet metal members and at least two connecting members firmly linking the sheetmetal members to one another, the levers being disposed radially to the housing and carrying, in vicinity of the inner radial end thereof and between the sheetmetal members thereat, a run-up member responsive to the action of an actuating member for actuating the pressure plate.

Abstract: In a friction clutch having a housing and levers mounted on the housing for actuating at least one pressure plate, the levers engaging the pressure plate through a connecting linkage, the levers being formed of at least two sheet metal members and at least two connecting members firmly linking the sheetmetal members to one another, the levers being disposed radially to the housing and carrying, in vicinity of the inner radial end thereof and between the sheetmetal members thereat, a run-up member responsive to the action of an actuating member for actuating the pressure plate.

Abstract: Friction clutch includes a pressure plate, a lever for actuating the pressure plate, and linkage means connecting the lever to the pressure plate, the lever being formed of at least two stamped-out sheet-metal parts and at least two spacer members holding the sheet-metal mutually spaced at a fixed distance from one another.

Abstract: In a friction clutch having a housing and levers mounted on the housing for actuating at least one pressure plate, the levers engaging the pressure plate through a connecting linkage, the levers being formed of at least two sheet metal members and at least two connecting members firmly linking the sheetmetal members to one another, the levers being disposed radially to the housing and carrying, in vicinity of the inner radial end thereof and between the sheetmetal members thereat, a run-up member responsive to the action of an actuating member for actuating the pressure plate.

Abstract: A reversing mechanism for two clutches wherein one of the clutches is alternately blocked in lifted condition, comprising actuating means movable over a disengaging travel path, for selectively engaging and disengaging the non-blocked other clutch, means comprising a stepping mechanism and a reversing device, the actuating means being movable beyond the given actuating path and over a reversing path for actuating the means comprising a stepping mechanism and a reversing device, and a lifting device connected to the actuating means and actuable thereby for effecting engagement and disengagement of the non-blocked clutch over the disengaging travel path (I-II), and at least substantially over the reversing path (II-III) and in a force transmission path between the actuating means and disengagement member of the clutches, the lifting device being effective so that at least over partial ranges of the reversing path (II-III) a change in at least one of the path direction and the force transmission occurs, the lift